Transfer maps to Garmin Zumo XT

I'm using Garmin Basecamp on a Macbook Air, using Parallels and Windows 11. I have just bought this computer and tranferred everything over from my old computer to this one. I can't see detailed maps now, only when I have my ZUMO plugged into the computer. There used to be a feature where I could transfer the maps from my XT to Garmin Basecamp, but I can't find it. Anyone know what the process is?